Standring D N, Venegas A, Rutter W J
Proc Natl Acad Sci U S A. 1981 Oct;78(10):5963-7. doi: 10.1073/pnas.78.10.5963.
A cloned yeast tRNA3Leu gene containing a 33-base intervening sequence (IVS) is selectively transcribed by a soluble extract from HeLa cells. The 130-nucleotide tRNA3Leu precursor RNA formed is colinear with the gene and contains approximately 4 leader nucleotides and up to 9 trailer nucleotides. The IVS is accurately and efficiently removed by an endogenous HeLa excision-ligase activity to yield the spliced tRNA, the free IVS, and the half-tRNA intermediates. The splicing reaction occurs without prior 5' and 3' maturation of the precursor but, with this exception, this pattern of synthesis and subsequent maturation of the tRNA3Leu precursor conforms to the scheme for tRNA biosynthesis deduced for the xenopus system. Indeed, the two systems utilize similar or identical tRNA3Leu precursors. Our results stress the extraordinary conservation of tRNA biosynthesis in eukaryotes and demonstrate that a HeLa extract provides a useful system for investigating this process.
一个含有33个碱基间隔序列（IVS）的克隆酵母tRNA3Leu基因被来自HeLa细胞的可溶性提取物选择性转录。形成的130个核苷酸的tRNA3Leu前体RNA与基因共线性，包含约4个前导核苷酸和多达9个尾随核苷酸。IVS被HeLa内源性切除-连接酶活性准确且高效地去除，产生剪接后的tRNA、游离的IVS和半tRNA中间体。剪接反应在没有前体5'和3'先成熟的情况下发生，但除此之外，tRNA3Leu前体的这种合成和随后成熟模式符合为非洲爪蟾系统推导的tRNA生物合成方案。实际上，这两个系统利用相似或相同的tRNA3Leu前体。我们的结果强调了真核生物中tRNA生物合成的非凡保守性，并证明HeLa提取物为研究这一过程提供了一个有用的系统。
